Computer Aided Style Design System Based on Highlight Lines

2009 ◽  
Author(s):  
Sakiko Yano ◽  
Hideki Aoyama
Keyword(s):  
Surface Shape ◽  
Free Form ◽  
Design System ◽  
Normal Vector ◽  
High Quality ◽  
Design Work ◽  
Design Processes ◽  
Normal Vectors ◽  
Free Form Surfaces ◽  
Unit Normal

Free-form surfaces are useful for modeling the external shape of industrial products but designers are still facing difficulty in designing high-quality aesthetic surfaces because commercial CAD systems currently available lack the required performance to support their design work. This has therefore led to the increasing need for design-aiding modeling systems to enhance the efficiency of high quality surface design processes. This paper proposes a method of redesigning aesthetic surface shapes by controlling unit normal vectors on the surface and discusses a fundamental system constructed based on the proposed technique. Attempts were also made to construct the required character lines using the proposed technique. Additionally, the validity of the proposed technique was also verified. In the surface evaluation stage of existing product design processes, the highlight-check method using highlight lines on the surface of a model is the most common and popular evaluation method even though methods using curvature and isophote have been proposed. With this method, the unit normal vectors on the surface are controlled by highlight lines. A highlight line is defined as a curve which consists of points with a constant angle to the right reflective direction when a beam shines on an arbitrary point on a surface. With this highlight-check system, highlight lines are displayed on the screen and evaluated by the designer. When highlight lines are faulty or those required by the designer cannot be obtained, the designer just needs to enter the required highlight lines manually by drawing with a pen tablet on LCD interactive display to improve surface quality. Usually, the system takes input highlight line information as unit normal vector information, and constructs the required surface shape using that information.

Multiple-Points Constraints Based Deformation for Free-Form Surfaces

1999 ◽  
Author(s):  
J. M. Zheng ◽  
K. W. Chan ◽  
I. Gibson
Keyword(s):  
Surface Deformation ◽  
Single Point ◽  
Displacement Function ◽  
Surface Shape ◽  
Free Form ◽  
Surface Model ◽  
Deformation Method ◽  
Multiple Points ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract There is an increasing demand in the conceptual design for more intuitive methods for creating and modifying free-form curves and surfaces in CAD modeling systems. The methods should be based not only on the change of the mathematical parameters but also on the user’s specified constraints and shapes. This paper presents a new surface representation model for free-form surface deformation representation. The model is a combination of two functions: a displacement function and a function for representing an existing NURBS surface called parent surface. Based on the surface model, the authors develop two deformation methods which are named SingleDef (Single-point constraint based deformation method), and MultiDef (Multiple-points constraints based deformation method). The techniques for free-form surface deformation allow conceptual designer to modify a parent surface by directly applying point constraints to the parent surface. The deformation methods are implemented and taken in an experimental CAD system. The results show that the designer can easily and intuitively control the surface shape.

Tool Path Generation Method for High-Quality Machining of Free-Form Surfaces

2020 ◽  
Author(s):  
Yuki Takanashi ◽  
Hideki Aoyama
Keyword(s):  
Tool Path ◽  
High Accuracy ◽  
Tool Path Generation ◽  
Free Form ◽  
Machining Accuracy ◽  
Path Generation ◽  
High Quality ◽  
Nc Program ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract Machining data (NC program) is generated by a CAM system, which generates the tool path from the target shape as a plane approximation surface instead of a free-form surface. Owing to this plane approximation, machining accuracy is reduced. In this paper, we propose a method to process the shape with high accuracy by defining the areas where accuracy is not required as a plane approximation surface and defining the part where accuracy is required as free-form surfaces.

Computing Offsets of NURBS Curve and Surface

2012 ◽  
Vol 542-543 ◽  
pp. 537-540
Author(s):  
Ying Yue ◽  
Jun Jia
Keyword(s):  
Curve Surface ◽  
Computational Time ◽  
Normal Vector ◽  
Unit Normal Vector ◽  
Nurbs Curve ◽  
Vector Direction ◽  
Normal Vectors ◽  
Offset Curve ◽  
Offset Error ◽  
Unit Normal

This paper presents an algorithm for the offsetting of NURBS curve/surface. First the unit normal vectors of the progenitor NURBS curve/surface is computed precisely, then the offset curve/surface can be obtained by offsetting the progenitor curve/surface in the normal vector direction with the required distance. Considerable extra computational time can be saved, especially when they are to be offset by several times. As the method successfully computes the unit normal vector of the progenitors, the offset error of this method is zero. The method can also be generalized to other degree NURBS curve/surface.

scholarly journals CONTROL METHODS OF OPTICAL DETAILS WITH FREE-FORM SURFACES AND KINOFORM ELEMENTS

2020 ◽  
Vol 8 (1) ◽  
pp. 118-126
Author(s):  
Nikolai Y. Nikanorov ◽  
Elizabeth G. Bobyleva
Keyword(s):  
Surface Shape ◽  
Free Form ◽  
Control Methods ◽  
Industrial Practice ◽  
Free Form Surfaces ◽  
Production Conditions ◽  
Methods Of Control

Methods of control of optical parts with free-form surfaces and kinoform elements under production conditions are considered. Two of the considered methods - interferometric (using holographic compensators) and profilometric (using contact profilometers) - are widely known and used in industrial practice. The method of non-contact profilometry, based on chromatic confocal sensors to control the surface shape of optical parts in industrial conditions, was not previously applied.

Algorithm for Tool Path Offsetting Based on NURBS Surface

2014 ◽  
Vol 945-949 ◽  
pp. 111-114
Author(s):  
Ying Yue
Keyword(s):  
Tool Path ◽  
Computational Time ◽  
Machining Accuracy ◽  
Normal Vector ◽  
Nurbs Surface ◽  
Unit Normal Vector ◽  
Vector Direction ◽  
Normal Vectors ◽  
Offset Surface ◽  
Unit Normal

This paper presents an algorithm for tool path offsetting based on NURBS surface. First the progenitor free surface is fitted with a bi-cubic NURBS surface and the unit normal vectors of the NURBS surface is computed precisely, then the offset surface can be obtained by offsetting the NURBS surface in the normal vector direction with the required distance. Considerable extra computational time can be saved, especially when they are to be offset by several times. As the method successfully computes the unit normal vector of the progenitors, the offset error of this method is zero. The method can also be generalized to other degree NURBS surface, and it can improve the machining accuracy of the surface.

A Golf Head CAD/KBE Optimization Design System

2011 ◽  
Vol 338 ◽  
pp. 304-310
Author(s):  
Yung Yuan Hsu
Keyword(s):  
Optimization Design ◽  
Secondary Development ◽  
Free Form ◽  
Design System ◽  
Solid Model ◽  
Development Environment ◽  
Cad System ◽  
Knowledge Based ◽  
Complex Design ◽  
Free Form Surfaces

The purpose of this study was to construct a knowledge-based CAD/KBE system for the optimal design of golf heads. The inability of conventional CAD systems to identify existing knowledge during design and manufacturing processes is a current development bottleneck. Therefore, this study attempted to effectively introduce and integrate KBE technology into a CAD system, so as to achieve the objective of knowledge driven automation (KDA). This study selected golf iron heads with a complex-design surface as the research subject, adopted commercial CAD software (UG/NX) and its secondary development environment as a platform and applied perturbation vectors in the control of NURBS free-form surfaces. We changed the CAD’s entity shapes and physical properties, integrated the optimal principle of design with a CAD solid model, to automatically drive the CAD solid model of golf iron heads according to the design objectives, and constructed a knowledge-based optimal CAD design technology.

Touch probe radius compensation for coordinate measurement using kriging interpolation

1997 ◽  
Vol 211 (1) ◽  
pp. 11-18 ◽  
Author(s):  
J. R. R. Mayer ◽  
Y. A. Mir ◽  
F Trochu ◽  
A Vafaeesefat ◽  
M Balazinski
Keyword(s):  
Computer Aided Design ◽  
Kriging Interpolation ◽  
Free Form ◽  
Probe Radius ◽  
Part Surface ◽  
Probe Radius Compensation ◽  
Normal Vectors ◽  
Radius Compensation ◽  
Free Form Surfaces ◽  
Touch Probe

Obtaining CAD (computer aided design) descriptions of actual parts having complex surfaces is a key part of the process of reverse engineering. This paper is concerned with the estimation of actual surfaces using coordinate measuring machines fitted with a spherically tipped touch probe. In particular, it addresses in detail the problem of probe radius compensation. A general mathematical model, using kriging, is proposed which first generates the initial probe centre surface and then estimates the compensated or part surface. The compensation is achieved using normal vectors to the initial probe centre surface at each measured point to compensate for the probe radius. The method is validated experimentally on known and free-form surfaces.

Development of Simultaneous Measurement of 3-D Shapes and Normal Vectors for Specular Objects

1999 ◽  
Vol 11 (2) ◽  
pp. 112-116
Author(s):  
Saburo Okada ◽  
◽  
Masaaki Imade ◽  
Hidekazu Miyauchi
Keyword(s):  
Optical Measurement ◽  
Maximum Error ◽  
Surface Shape ◽  
Normal Vector ◽  
Curved Surfaces ◽  
Vector Data ◽  
Optical Position ◽  
Normal Vectors ◽  
Specular Objects ◽  
Shape Data

Our research institute developed and built an experimental optical measurement system for specular objects able to simultaneously measure 3-D shapes and normal vectors of surfaces to measure shapes of objects with mirror-finished surfaces and to restore original shapes accurately by inputting measured values in CG and CAD systems. A semiconductor laser spotlight is irradiated on the measured surface vertically or obliquely. Space coordinates of rays reflected on the surface are instantaneously measured at 2 different points in space using optical position sensors rotating at a constant speed. The 3-D coordinates and normal vectors of the reflection point are obtained geometrically. A performance evaluation using a metallic semisphere with a mirror-finished surface showed that the system simultaneously measured 3-D displacement and normal vectors of specular curved surfaces of any angles up to 20 degrees, with maximum error of several degrees in normal vectors and several millimeters in surface shape. The developed system may restore higher quality curved surfaces than conventionally because it reconstitutes curved surfaces using both measured 3-D shape data and normal vector data.

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